Ok, here is what i did, I just picked up the 2700mh battery from verizon, kind of for an experiment, but also for the fact that battery life is needed. I hate the extended battery cases that verizon sells, and there arent any aftermarket ones to speak of.....I really like the defender case and there for am still using the defender case WITH my extended battery. To do this, I had to carefully cut out a spot just big enough for the battery to fit through the back of the original htc back cover of my phone. Then very carefully cut out a place for the battery to fit through the back half of the otterbox defender plastic case. I know, pretty redneck and hillbillyish, but wait!!! im not done yet....lol I cut the holes just big enough that the battery fit tightly through them both. Next, I placed a piece of heavy strapping tape across the back and also across the inside of the back. I did this to ensure that there was still a complete seal with the case, and also it holds the battery from being jarred loose from a drop or anything else. After all that, I put the rubber sleve back onto the defender case and voila!!! I have the extended battery with the otterbox defender case, and you cant even tell. I even did a few test drops onto a wood floor from desk height just make sure that there were no problems, and there werent!... I have pics to show what i did and where I cut if any one is interested.... Good luck!:blink: